1. Field of the Invention
This invention relates to the disposal of concrete and wash water that is produced when various items of concrete-handling equipment are cleaned. More particularly, it relates to a method and apparatus that enables such concrete-handling equipment to discharge concrete washout residue into a bin without requiring the equipment to be lifted to the level of the rim of the bin.
2. Description of the Prior Art
It is imperative that residual concrete be washed from concrete-handling equipment at the end of each work day. Failure to do so results in a gradual build-up of hardened concrete in the equipment. Such build-up may reduce the amount of usable concrete that can be delivered to a job site and it may increases the taxable weight of “empty” trucks or other equipment subject to taxation by weight. Studies have also shown that even small amounts of hardened concrete in equipment act as seeds that serve to accelerate the rate of build-up. If the problem is ignored, the amount of hardened concrete becomes substantial and the removal thereof is very problematic.
However, it is unacceptable from an environmental standpoint to simply wash out the inside of a ready-mixed concrete truck drum, a concrete boom pump truck, a hopper that receives concrete from a concrete boom pump truck, or other concrete-handling equipment with a water hose, so that the residual concrete is washed onto the ground. The wash water contains caustic soda and potash and therefore is classified by the Water Quality Act (part 116) as a hazardous substance. Accordingly, the Environmental Protection Agency requires the owners and operators of concrete-handling equipment to handle and dispose of the wash water as a hazardous substance, to maintain records of such wash water disposal for three (3) years, and to submit the records to the EPA when required.
Most companies that handle concrete comply with the requirements by collecting the wash water in a bin or receptacle and by transporting the filled bin or receptacle to a treatment facility such as a settling pond or the like. A typical bin has a rim that is about twenty to twenty four inches (20-24″) above the ground or other support surface upon which it rests. Unfortunately, such elevation is too high for some concrete-handling equipment to reach. For example, the hopper that receives concrete from a boom pump has a funnel-like discharge downspout that is below the level of a typical washout bin. Such hoppers are too heavy to economically lift to a level where they can be positioned over a bin. Thus, owners of such hoppers and other such concrete-handling equipment are presented with a problem when told they must discharge all washout water into a bin that is higher than such equipment was designed to discharge into.
One solution to this problem is to provide a ramp that extends from the ground surface up to a level that is sufficiently elevated to enable a concrete-handling truck to back up the ramp and deploy its discharge chute above the rim. Published U.S. patent application No. US2004/0155126 discloses this solution to the problem.
However, the provision of a ramp may not be the optimal solution to the problem. Many concrete-handling trucks weigh about thirty-five (35) tons and are most stable when all wheels are on the ground. Backing such a heavy truck up a ramp is a risky maneuver and probably violates one or more OSHA safety regulations. If a wheel slides off a ramp, the results can be catastrophic, totaling the truck and placing the life of the driver in jeopardy. At least one such incident has already been reported since the advent of the EPA requirements and the introduction of ramps that enable compliance.
There is a need for an apparatus and method that enables the concrete-handling industry to comply with EPA requirements without ramps or other devices that cause heavy trucks to leave the ground.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how the identified need could be fulfilled.